title: Do sleep abnormalities and misaligned sleep/circadian rhythm patterns represent early clinical characteristics for developing psychosis in high risk populations?
abstract: Sleep architecture changes, such as slow-wave sleep (SWS) percentage variations and reductions in latency and density of rapid eye movement (REM), are found in most patients with schizophrenia and are considered to be an important part of the pathophysiology of the disorder. In addition to these sleep parameters changes, disruptions in sleep homeostasis and the sleep/circadian rhythm also occur in these patients. Sleep/circadian rhythm abnormalities negatively affect neocortical plasticity and cognition and often precede the diagnosis of the illness. Thus, it has been suggested that the sleep/circadian rhythm might be involved in the pathophysiology of psychosis. Recent advances in the identification of individuals at a high risk for developing schizophrenia allow us to investigate several neurobiological processes involved in the development of psychosis. In this article, we review the current evidence of the effects of sleep parameter abnormalities, disruptions in sleep homeostasis and misalignments of sleep circadian rhythm on the early stages of schizophrenia. In addition, we discuss the preliminary evidence of sleep and circadian rhythm abnormalities during the prodromal stages of psychosis and propose that these abnormalities can be explored as potential predictors, as an adjunct to clinical diagnosis, of developing a psychotic disorder in at risk populations.
authors.affiliation: Programa de Reconhecimento e Intervencao em Indivíduos em Estados Mentais de Risco (PRISMA), Departamento de Psiquiatria, Universidade Federal de Sao Paulo, Sao Paulo, Brazil. Electronic address: marcioazanini@gmail.com.
authors.forename: Marcio
authors.initials: M
authors.lastname: Zanini
authors.forename: Juliana
authors.initials: J
authors.lastname: Castro
authors.forename: Fernando Morgadinho
authors.initials: FM
authors.lastname: Coelho
authors.forename: Lia
authors.initials: L
authors.lastname: Bittencourt
authors.forename: Rodrigo A
authors.initials: RA
authors.lastname: Bressan
authors.forename: Sergio
authors.initials: S
authors.lastname: Tufik
authors.forename: Elisa
authors.initials: E
authors.lastname: Brietzke
mesh_terms: D021081:Chronobiology Disorders / Q000209:etiology*; D006801:Humans; D011618:Psychotic Disorders / Q000150:complications* / Q000453:epidemiology; D012307:Risk Factors; D012893:Sleep Wake Disorders / Q000209:etiology*
keywords: Circadian rhythm; Psychosis; Schizophrenia; Sleep; Ultra High Risk